From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [95.215.58.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C929012C7FB for ; Thu, 4 Apr 2024 19:00:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712257238; cv=none; b=QS2muNeXYMSSycsXTPl6Xu74BMm26VnfyO/1oogI+akmuMxJq0eZw3OcwJNk9Okyv2Wgo8FBBMN6IQ/RkF9aM2BKw9b8QNagUv1IQd9xQw/sCKcKquij5W+UaWdj/PCuFJlgu1BSWtZMmVsmcxfGBH0lKDzAc94+4Tu52PUQWPQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712257238; c=relaxed/simple; bh=sbbwP4m8hODhTvUlJxQ9gw6z8fPxCf3pdA3GY9BOP58=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=T7OE20SENT4+RbdifA7HoFL1eh8LTIdpOdHI4eWCl3jz2JUhzSrX7FtRAzLWy+DqhxoBFaFLAx3JB+ae/rExvWbUMMw5l7fPk/NYU1xKbufFKYzpjKXsH3M9FgPNuFG8ORFIJ4OJgROMCIbArAzpzOc8kLxEuRDHlWCf6uZXxU4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=w7WrLvK8; arc=none smtp.client-ip=95.215.58.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="w7WrLvK8" Message-ID: <110c4768-2294-436e-a96a-7063bae85ee7@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1712257218; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=sbbwP4m8hODhTvUlJxQ9gw6z8fPxCf3pdA3GY9BOP58=; b=w7WrLvK8Y1ywCKqh3erOTr6gfYJoIk760WqMipeqVSAQ1CyewsmG8DR5lDQbwTBS1plgfR +XkvQdIbyOEFEruYKN2ex9LrBq+n2iQ51we3hAZ6I2uSvRxyHE6EYpjVVj4xRfXWVcHftQ FD0PpekVP4AhkWiKv6vFlFgwpRwt4Gc= Date: Thu, 4 Apr 2024 12:00:11 -0700 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [syzbot] [bpf?] KMSAN: uninit-value in trie_delete_elem Content-Language: en-GB To: Aleksandr Nogikh Cc: Alexander Potapenko , syzbot , andrii@kernel.org, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, eddyz87@gmail.com, haoluo@google.com, john.fastabend@gmail.com, jolsa@kernel.org, kpsingh@kernel.org, linux-kernel@vger.kernel.org, martin.lau@linux.dev, sdf@google.com, song@kernel.org, syzkaller-bugs@googlegroups.com References: <000000000000f9ce6d061494e694@google.com> <2ee098ec-a46f-44fa-8719-049331c4c206@linux.dev> <02d29315-13ee-45c1-984e-13c98e88247b@linux.dev> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Yonghong Song In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT On 4/3/24 1:47 AM, Aleksandr Nogikh wrote: > On Wed, Apr 3, 2024 at 5:59 AM Yonghong Song wrote: >> >> On 4/1/24 11:36 PM, Aleksandr Nogikh wrote: >>> Hi, >>> >>> On Mon, Apr 1, 2024 at 8:55 PM Yonghong Song wrote: >>>> On 3/26/24 12:00 PM, syzbot wrote: >>>>> Hello, >>>>> >>>>> syzbot found the following issue on: >>>>> >>>>> ===================================================== >>>>> BUG: KMSAN: uninit-value in trie_delete_elem+0xc0/0xbe0 kernel/bpf/lpm_trie.c:448 >>>> Unrelated to the bug itself, with KMSAN is enabled, qemu cannot boot my vm >>>> any more. Anything special I need to do in order to boot a KMSAN kernel? >>>> >>> Does the kernel print any specific errors to the serial console while >>> booting? Or nothing at all? >> In my case, nothing at all. >> > If you're using qemu, please try adding "-machine pc-q35-7.1" to its > arguments. Otherwise it's known to have problems with very large > kernel images. I still do not help. My qemu does not support pc-q35-7.1. The most q35 machine is pc-q35-5.2 and it does not work.